The long-term objective of this proposal is to understand how mammalian cell proliferation is conrolled and how transformation alters normal growth control. The specific aims are to determine how platelet derived growth factor (PDGF) and epidermal growth factor (EGF) initiates cell proliferation in various cell lines. It is important to understand if these two growth factors have a common mechanism. Another aim of these studies is to determine if the proteins induced by PDGF are responsible for the competence state. These proteins will aslo be analyzed in transformed cells. The interactions of several plasma-derived progression factors will also be investigated to determine how they effect cell growth and the response of the cells to each other. These studies will provide a better understanding of how cancers arise. They will also help explain how growth factors control growth and development by investigating how hormones and growth factors function. During the course of these investigations we will use autoradiography, gel chromatography, single and two dimensional SDS polyacrylamide gel electrophoresis, and preparative isoelectric focusing. Successful completion of our aims will yield a model system to investigate the regulation of cell proliferation.